Synthetic Oil
by Emo Fox
Summary: Zenyatta wants to help Genji through his rut. {O-verse} {Alpha!Genji/Beta!Zenyatta}
1. Artificial

During this time of the year Genji preferred to embrace what made him human.

Zenyatta knew his student could choose to mellow the reactions in his body, could choose to shut them down completely, but he had never done so. His omnic body when created had been done with the intention on making him a 'beta' for all extents and purposes. Though he had told him before, upon being reconstructed he had pleaded to have his gender intact, in any way it could still be.

It had been years since he had found Genji Shimada, full of rage, ready to pick a fight with the mountains themselves. Years since he had tempered that anger and carefully guided the young man back into gentler waters. Years since he had forgiven his brother(whom now resides within Overwatch) and exactly two years since they had become a 'mated' pair.

Mated pair was not the actual term for what they were.

They could not bond in the traditional way. Zenyatta could not bite and in return nor could he be bitten by organic teeth. Every part on his body was made of the highest grade of steel, originally built as a service robot, one to work hard labor. It took a lot to bend or break any piece of his machinery, and even with all of Genji's strength; both organic and enhanced, he could not break or bend Zenyatta should he ever want to.

Of course, he could cause damage to his wiring, the delicate system which resided between the nuts, bolts, screws, pistons, bearings and all other such materials.

But harming him in any way was not Genji's intent, not anymore, and not during this time of the year. Zenyatta could feel it, almost aware of the bone deep ache Genji exuded, similar to the rage he had felt in him before. Just something he was in tune with, something he could pick up on by just being in the same room as his student.

Genji wanted to mark him, he wanted to experience him as an alpha should.

Zenyatta, for all extents and purposes, was created as a beta.

Originally he didn't have any sexual components. The upgrade came later, when he was certain of Genji's affection, when he was certain he had likewise fallen for his student and wanted to experience all he could with him. He had a similar ache to be close, to give and take whatever he could from the human in which he had fallen so deeply in love.

Despite that upgrade, he still smelled like a machine. Like synthetic oils, something sweet and bitter all at once. Tasted like metal, everywhere except at his core, to which he was certain he merely tasted like whatever lubricant he had refilled. Genji was perversely detailed when telling him things about himself, especially when they were intimate.

Zenyatta loved that open honesty, it made him feel wanted and adored.

But it also brought him to his current plight.

Genji was an alpha.

Each time he went into rut he was never fulfilled. His knot(though he could inflate it by artificial means) would not form from sexual activity, no matter how much he willed it, no matter how much he tried.

His previous rut cycles had ended in an emotional slump.

Genji would take weeks after alone, to mediate, to come back to himself, to remember he was of two bodies now, and the one he had chosen to love didn't have a body at all.

Zenyatta felt he was in pain when Genji was in pain.

They had discussions before, of Genji leaving, of pursuing someone who could fulfill him in the ways Zenyatta could not. Those conversations were short, and only angered Genji more. There were no doubts in his loyalty, nor his love. They hadn't spoke of those matters in a long time. But, after his last failed rut, Genji had decided they should be apart for them.

Zenyatta respected his decision.

This was the first day of Genji's cycle.

He was likely outside the temple, either training or meditating. Anything to take the edge off, as biology tried to take him over.

But, Zenyatta had formulated a new plan, and he wasn't one to sit by while his beloved suffered. He would not force him any which way, but he definitely wanted to try and make this different, to be able to please Genji in all the ways he could.

Unbeknownst to the ninja, Zenyatta had procured concentrated doses of scent. Specifically, omega heat scent. Currently, the monk was sitting in his room, the fading light of the day peering in through the open window. He was kneeling on a woven rug, across the floor in front of him were seven hollowed bolts with smooth capped tops. Inside the bolts was a golden liquid, shimmering faintly where the light caught. To the right of them laid Zenyatta's seven nodes, sensitive 'buttons', these specifically were from the places on his body where scent glands would be. Two from his throat, one from the back of his neck, two under the joints in his arms, and two from his 'thighs'.

Zenyatta didn't know what the scent smelled like. He had only been assured it was the purest on the market, that it would fool even the best nose. Zenyatta's body though advanced, did not come with the ability to smell and taste. He could only perceive through his other senses, the capped nodes on his body, to which he had many, allowed him to touch and feel. These were the most sensitive, the ones he had dug out and placed on the floor, and now he could have them exuding the aroma Genji was looking for during this time of the year.

It was exciting, and terrifying all at once.

There was always a chance the man he had bought the scent from was lying. While he wanted to believe the best of people, he was not ignorant to the reality of the world, and understood that anything on the markets for omnics was expensive and with things such as this, often worthless.

He had never seen Genji really lose himself to his rut. His student never had the trigger before; though the ninja had been explicit in what he used to experience, what he used to expect. He had never gotten the same heightened pleasure with Zenyatta and he knew that he ached for it in the same way Zenyatta ached to provide it.

Zenyatta's fingers did not shake despite the nervousness that started to flutter in his chest as he replaced the nodes with the scent filled ones. One by one he snapped them in place before he picked up his own pieces and set them aside in a box for when they needed to be replaced. He had already filled up his lubricant canister(a thin tube just above his 'pelvis') with a synthetic blend of omega slick(the man had told him it would taste like honeysuckle). Last was the small squirt bottle of his omega heat scent, supposed to be used in the room to which he wanted to be mated in, and possibly as a trail to lure his alpha.

None of the other monks could smell either, so Zenyatta didn't have to worry about anyone catching on to any changes. Everything on Zenyatta's body looked exactly how it should, and despite walking around the monastery now squirting his little bottle of artificial scent, no one really cared to ask him about it.

His excuse, if asked, was just that he wanted to bring a pleasant scent for Genji's nose.

They did use candles and incense in prayer, but obviously not for the smell of it, more the ritual of it. Though Genji often told him the open air temple smelled saturated with it at times.

Wherever his lover was off to, he'd be back, at the least to wait out his rut in his room. He knew Genji would start getting restless, and being out in the open air would only rile his instincts to get back to his den, back into safe territory.

Zenyatta knew Genji wouldn't join him in his room; so that was the reason he had found himself instead to Genji's. He had sprayed the smell there, just inside the doorway, letting the scent hang in the air from the hallway and beyond. Zenyatta could only hope the smell caught and lingered, that Genji would follow the trail to Zenyatta's room(if that is what his mate wanted to do).

His task completed, Zenyatta had retreated back to his quarters, and waited.


	2. Scent

Being outside was supposed to clear his head.

Despite the chill of the wind, the crisp air in his lungs, and the fading sunlight warming his face(his face plate lay on the ground near his right hip); he could not find peace. No matter how long he sat, no matter how hard he tried to clear his mind, peace did not come.

He could never find it, not during this time of the year.

His base instincts were roiling under his flesh like maggots. Incessant and impossible to ignore; the need to fuck, breed and claim taking precedence over all other thoughts. The instinctive loop of needs circling back to thoughts and images of his mate and where he was right now.

Somewhere in the temple; alone, unguarded, waiting.

But, he could not go to him.

The three days of his rut were torture for both his mind and body. He could not seek Zenyatta because he could not be satisfied in the way he wanted. His body only craved, getting worse and worse and he felt guilty to project that frustration on his beloved mate.

He had made this decision, for the both of them.

It didn't stop his body from wanting, and it physically started to hurt being away from Zenyatta. Knowing he was somewhere alone, all his instincts wanted him to go to him, to be sure he was safe, to fuck him until this pain inside of him was gone.

Zenyatta was strong and could take care of himself; probably even stronger than he was.

But, logic couldn't always punch through the panic of instincts and he knew sitting outside just wasn't going to happen for much longer. Not when things were ramping up and he couldn't clear his mind.

With great reluctance he got up from his sitting position and replaced his face plate. The snow crunched beneath his feet, the fading sunlight casting everything in a bright orange glow. He couldn't go to Zenyatta, and knew his lonely den was the only thing waiting for him, three days to burn out his fever before he could reunite with the monk who had stolen his heart.

Eventually he made it back to the monastery, the monks he ran into he only offered a nod. Not in the mood for pleasantries.

Once he entered the temple he smelled it.

At first he didn't know what it was, but the scent melted through his filters and laid heavy on his tongue. Not incense, or candles, or even pine burning.

This was something his primal brain began to recognize, something he hadn't smelled first hand since his youth. He hesitated in the hallway, head tilted up and scenting the air like an animal as the warmth of it washed over him.

Omega in heat.

But it was wrong to want it; his logical brain catching up to his animal needs.

Zenyatta was his mate. Surely the temple had just sheltered in a stray. But he couldn't help but follow the smell. Walking down the hallway, trying to follow the path which was leading closer and closer to Zenyatta's room.

It seemed fitting his teacher would be the one to harbor the person in need. Like he had done for himself years ago. Here he hesitated, fighting with his want to at least look at the omega, satisfy some part of him.

Gently, he tapped on the door, "Master, can I enter?" He asked, his voice more rough than intended, deeper even with the modulator in his face plate.

"Yes you may Genji." Came the reply, and though Zenyatta's voice was nothing but solid, something made him feel as if it were off somehow.

Genji opened the door enough to slip himself inside, and here the scent was strongest. Warm and thick like honey, grateful his faceplate was in place to hide the obvious flush to his scarred skin and the darkness to his eyes.

But where he expected to find Zenyatta and some unknown person, the room only housed his mate.

His head still foggy, he couldn't help but look from one part of the sparsely furnished room to the other. Zenyatta was sitting still in the center of his meditation rug, his head tilted towards him and the ambient blue lights on his forehead solid in the gloom of the room. Candles were burning on the low dressers and the small table.

The room smelled so much like heat, like sex, that he still couldn't link the scents to his teacher.

"Is something the matter?" Zenyatta asked neutrally.

"Just," Cautiously, he removed his face plate, setting it down before he kneeled near Zenyatta. His brows were furrowed as he stared at his teacher, knowing that soon he'd need to leave, but he still wanted to understand where the smell had come from. "Did someone come in here? Pass in our temple?"

"Why do you ask?"

Genji couldn't help but growl; his patience much thinner in rut. His mate didn't react to it, stayed as steadfast as before and it made him grit out a response, "It smells in here. Why?"

"What does it smell like?" The small inflection to the question was almost taunting, playful.

His nostrils flared as he huffed, eyeing his teacher as if he were hiding this unknown person under him like a chicken would an egg. "Zenyatta." He spoke carefully, "It smells like heat."

"Does it?" He said in that same playful tone before he decided to add, "Where is it coming from?"

Genji squinted at his mate with suspicious eyes before he glanced around the room and lifted his chin to take in great breaths from the air like a dog. The entire space smelled like heat, he couldn't follow any singular trail. Thick and cloying, just everywhere, and it wasn't like there was anywhere in the room to hide anyone.

Maybe someone had just passed through? Maybe the room just needed to be aired out?

But Genji selfishly didn't want it to be, he wanted to inhale this heat smell and roll himself in it. A luxury of something he couldn't have, since the person he had chose to be with was a robot, a beta for all extent and purposes. He had made peace with that, had settled on this arrangement of theirs, and until he had smelled the heat now-

He hadn't entirely let himself fantasize about what he was missing. From being with a true omega and all the fixings that came with that.

Barely aware his mouth was slightly open and he kept scenting the air, feeling the warmth pool in his guts and his rut take a hold of him more securely. "Everywhere." He finally answered, his voice a low almost purring growl.

Zenyatta shifted on his mat, affected by his mate's deep rolling voice. "Your nose is better than that." He chided softly.

Genji decided to indulge Zenyatta, pacing around the space and circling here and there. He tried to follow the trails but there was just so much of it everywhere it felt more like a cloud than any real paths.

His fingers touched over the top of the dresser, bent low to the table in the center of the room as he walked here and there. The further he got from Zenyatta, he noticed the smell wasn't as rich. So, finally, he could understand a source, or at least the main concentration.

Just a few more circles of the space and he was finally convinced that yes, the smell was strongest coming from Zenyatta. Which had Genji finally kneeling back in front of him, close, sharing the same threadbare carpet in the center of the room. His hands were on his knees, his legs under him, but his body pitched forward towards the monk.

"Well?" Zenyatta prompted, his head still tilted in that curious way.

"It is strongest around you." He said, his brown eyes almost black with lust, could almost see his own reflection in the shiny chrome of his mate's faceplate. "But that is impossible."

"Nothing is impossible, Genji." He said with that same playful tone, leaning in just a little, this time openly displaying his throat.

It was such a submissive, animal display that Genji for a moment didn't even know what to do with it. But here he could smell it better, like a dose of heat smell had just been thrown at him. His mate's throat exposed, letting him see the delicate wires that twined just under the thick metal of his spine. The concentration of the wires buttoned up by nodes, a shiny pin on either side of his neck.

Zenyatta had many nodes in his body, usually at joints or other points of intersecting wire, cable and metal.

"I don't understand." Genji finally managed to say, his mouth wet, almost salivating at the idea of biting into those wires, in smelling more of this heat scent, of finally having a true rut with the person he had chosen to spend his forever with. He was growing restless with the need to sate himself, but he couldn't bring himself to leave, to handle things alone like he had been used to doing.

Too caught up in the bizarre to let the hope and possibility go just yet.

"I may have went to great lengths to spend your rut with you." Zenyatta finally said, still displaying his neck for his alpha, who was showing immense restraint given the situation he was in. He selfishly wanted Genji to lose control, to really feel what it was like. To erase the memories from before, of frustration and impotent rage. Of leaving Genji unfulfilled, which had led to these separations in the first place. "I wanted to give you what you needed."

"What did you do?" Genji asked after a moment, his gaze hyper focused, his hands restless in his lap.

"I merely procured omega heat scent. I put the artificial smell in my nodes. I also bought heat slick." He let that sink in a moment, knowing exactly where Genji's mind would go. If he could smile he would have, when he saw his alpha's eyes flick downward, staring at the fabric over his crotch. "I may have also downloaded certain scenarios. To make this as realistic as possible for you."

"You," Genji's eyes snapped back up, "You downloaded porn?"

Zenyatta's voice rattled with a laugh, "Something like that, yes."

"Zenyatta-"

"Genji," He cut him off before he could continue, "While I appreciate your restraint and patience. Marvel at it, really. I actually had hoped for you to lose your mind over me. Isn't that how it is in movies?"

It was Genji's turn to chuckle, offering a wolfish grin that showed off his sharp alpha teeth. "Is that how you want me? Wild over you?" He taunted, pitching forward just a little more.

"Yes." He said plainly.


	3. Victory

Genji didn't just close the distance and ravish him, much to Zenyatta's dismay.

No, his alpha kept him pinned with his heated stare and kept him anxious with the sultry upturn of his mouth. It was feeling more like he was a true omega as he sat there, wanting to squirm under that gaze(yet his body was as rigid and steadfast as always).

"You've been thinking about me." It wasn't a question, and slowly(much too slowly) Genji was creeping into his space, closing the gap on his hands and knees.

Zenyatta pitched back, enough to allow the alpha room when Genji started to crowd him like he wanted. Letting the man hover over him, feeling a jolt of pride at the way Genji was scenting at him(subtle as it was, just a flare of his nostrils). "Of course, I did this all for you." He replied easily and delighted in the guttural purr he was rewarded with.

Genji rarely indulged his animal instincts with him; this primal side. Rare to hear him purr.

"Just for me." He said, flashing his teeth before he nosed along the omnic's jawline. "All for me."

Zenyatta felt his body warming; his core starting to heat up from the influx of sensory information coupled with the thread of emotions flowing through him. Genji's mouth had started to tease the delicate wiring under his jaw; great huffs of breath steamed his metal frame when the alpha lipped at his node(or scent gland, as he had artificially tried to make them). "Yes." He couldn't help but respond, tipping his head back and getting a pleased growl for his effort. "Yours." His hands felt like they should be shaking when he reached to touch at his mate(but of course they weren't, his programming wasn't suffering any malfunctions even if he was processing much faster than he usually did, and his reflexes were just as sharp).

They'd coupled countless times before; but never like this. This primal animal need had never been sated in Genji before, and Zenyatta desperately wanted his alpha to experience a true rut with him.

Where the anxiety and the worries wanted to flow through him, he trampled them down with shaky confidence and eagerness.

Genji didn't pick up on any of Zenyatta's emotions; not able to smell them, nor able to tell from his non-trembling body, there was little to alert him to anything that might be wrong without his mate explicitly telling him.

But, there was nothing wrong. Zenyatta just wanted it to be perfect. It would be perfect, he believed in that.

All at once Zenyatta was smothered to the ground and his voice box warbled a static response to the treatment. Pleased; his fingers touched along Genji's frame and felt the muscles work under his sensitive digits.

Genji continued to nose, lick and nip at the places along the column of his neck. Giving Zenyatta a feedback loop of pleasure that had him finally truly squirming under the alpha, producing more slick which his mate clearly smelled if the snarling response was any indication.

Genji may have started strong, but he was quickly devolving, and it was beautiful.

"Please." Zenyatta said, hands roaming down the man's hips, trying to nudge under his abdomen to release his cock. "I've waited all day for you my sparrow, give me what I need."

"Always." Genji had groaned into the pistons along his collar, spreading his legs and letting his mate's clever fingers release the privacy panel over his groin. Less than a moment later his cock had sprung free; leaking fluid onto the robes Zenyatta still wore where they were pressed together. "My omega."

Genji was in the right headspace, lost to the smells and taste of Zenyatta. But, there would be a moment of truth later, if this artificial heat scent could truly fool Genji's mind and body.

He'd never been knotted before, but he wanted it so badly he felt he'd short circuit if he couldn't feel it tonight. He didn't want to remember all the times before when Genji plunged into depression, when his body hadn't been good enough for his alpha.

Tonight would be different. It had to be. He believed in it.

It was a scramble to get himself out of his clothing, Genji helping after a moment of squirming, the entire event feeling like the first time they ever had sex. Just all sensation and fresh emotions; ravenous for each other as if they were the last two people on Earth.

Zenyatta wished he could smell his mate, could taste him. Knew he'd probably be pumping the room full of pheromones by now. Would probably smell delicious, would taste just as good. He'd never wanted a flesh body more than he did when he had sex with Genji; knowing there could be a transcending moment of touching flesh to flesh that they would never obtain together.

But Genji had never shown desire for anyone else. The man had a way of making him feel like he was the only thing in his universe. It was marveling, and like now, made him feel as if he were drowning in the sea of all these sensations.

Barely aware when he had become naked, when Genji had settled between his legs more firmly, when he could feel the press of the alpha's cock against his most intimate place.

"Zen." Genji was looking at him, beautiful honey brown eyes blown black, his lips wet and swollen from all his biting and kisses, "Need you."

Even as he lost his mind he was always seeking assurance, permission. Their dynamic even here, even with his mate jumping into the deep end of his subconscious animal brain, he still took the moment to check in on him.

He loved Genji more than he loved life itself.

"Please." He said again, tilting his head to display his throat in a way he knew would entice the alpha, "Claim me."

That was enough.

Genji planted himself more firmly over him, leaning down to place messy kisses against his faceplate in nonsensical patterns as his dick started to press against his valve. Didn't need any further coaxing; neither in the mood for foreplay, Zenyatta was more than slick enough to accept the intrusion.

Didn't take more than a couple seconds for the alpha to bottom out with a deep satisfied groan that had Zenyatta responded back with a reedy sound of his own.

"Yes." Genji grumbled against his face before he forcefully nosed his head to the side, biting harder against the wires in his neck and causing Zenyatta's entire body to shiver and jerk against him, "Mine."

Those sharp teeth snagging on his delicate wiring had him shaking involuntarily; how easy it would be for them to snap, how easy it would be for Genji to essentially 'rip his throat out' and leave him silent and broken as he took his cock.

The fantasy made his voice box fritz which only furthered his alpha's ministrations until finally, finally he felt the man pull out and slam back in.

Always so good; the burn, the feeling of being full, of becoming one with his mate.

Zenyatta held onto him, whispering words back; nonsense things to fuel the alpha into fucking him harder. Sliding across the floor on his woven prayer mat; one of Genji's feet having kicked out to grab more traction and ultimately toppled the table and broke all the dishes that were on top of it.

Genji snarled at the noise, tensing but not stopping the brutal pace he had set.

He couldn't help but coo, gently petting at Genji as he tried to stay afloat above the intense pleasure of it all; his foolish alpha hadn't registered the noise was from himself, and maybe had even thought someone had come to bother him.

Even if his brothers and sisters didn't understand the relationship he and Genji had; none were foolish enough to ever intrude on their couplings.

There was no one else but them, they had nothing to worry about.

He felt like that, floating above everything; grounded by Genji's huffing breaths and the snag of his teeth to the grueling pleasure that burned through him with every erratic thrust of his mate.

"Genji." He had moaned after a moment, nudging against the man's face in an animal way, lifting his legs up so the alpha could pump at a better and deeper angle(and didn't that just feel amazing?). "I need you," He said, letting his voice sound breathless(even though he didn't need to take any breaths at all), playing into the fantasy of the moment as he whined soft, "Please!"

"Got you." Genji grunted back, body relaxing back against him, smothering him in his warmth and his scent(though Zenyatta of course couldn't smell his attempt), "You're safe. You're mine." He growled soft, mouthing along his collar again, his hips starting to stutter against him, losing pace(he was getting close), "I got you."

His sweet protective, doting alpha. "Genji!" He trilled his voice on purpose, enjoying the snarl against his chest as the alpha drove into him for all he was worth, responding to the sound of his desperate need, "Knot me Genji, I need it!"

"Fuck." Genji gasped against him, deep thrusts turning into sharp rabbiting things; chasing an end.

Zenyatta was feeling close as well, giving into the pleasure, letting his walls tighten against Genji each time he pressed in, even with the erratic pace. He wanted his knot so badly he was developing tunnel vision for it; arching his body and doing everything he could to try and get it to happen. "Breed me." His voice was wanton and obscene.

That did it.

Genji grabbed his hip and yanked his body up to meet him, practically spearing him on his cock(as if he wasn't being pounded hard enough before)-

But there it was.

"Oh-!" Zenyatta didn't have words, his body truly trembling when he felt the pressure and the pop; his valve trying to latch around the bulbous base of Genji's cock. All at once he felt the flood of warmth as his alpha released inside of him and felt the burn of the stretch as his knot plugged him up.

It was enough to get Zenyatta to come; just on that sensation, of being full to bursting.

It took him a few moments to come down from his orgasm; it felt almost as if all his functions had gone offline only to burst back online seconds later. It was the most intense orgasm he had ever felt, and even now the little shock waves that were happening after were more delicious than anything he had ever felt before.

Genji was panting above him, propped up on his elbows now, barely any space between them where they were pressed together.

Zenyatta could withstand the weight of a car; it would take a lot of pressure for his body to bend or be crushed. Yet, Genji always acted as if he were fragile, even now exerting effort to prop himself above him rather than to lay all his weight on him as if Genji's one-hundred-eighty pound body would harm him at all.

It was always a sweet gesture, and in moments like this, he could feel a little human.

"Are you with me?" He asked, gently easing the alpha down to a full laying position; not finding any discomfort in his body nor his joints as his legs remained wrapped around the alpha, joined together by his amazing knot.

"Mm." Genji replied, and it wasn't much of an answer. He nuzzled under Zenyatta's chin, huffing breaths against the 'scent glands' in his neck, obsessed it would seem with the smell of them.

It didn't appear Genji was lucid enough to discuss the moment, or even completely understand the implications, nor the victory of it all. So he let him lay there, lifting a hand to run his fingers through his messy black hair. Petting him soft until his breathing evened out and the alpha sagged completely against his frame in slumber.


End file.
